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Date Posted: 17:37:59 05/11/01 Fri
Author: Chris Lawson
Subject: Re: Missing J78/J79 new directions
In reply to: Chris Lawson 's message, "Missing J78/J79 new directions" on 17:29:03 05/11/01 Fri

Forgot the most important part...

We now know that J79 simply connects pins 20 and 3, and J78 connects pin 20 to a few other pins, all of which appear to be ground pins. (Take off the metal shield on the top of the connector and you can see jumper J54, which appears to connect pin 25 to ground.)

Since removing J78 (and applying it - or a solder bridge - to J79) seems to be integral to the modification, I propose the following is why it works:

In order to achieve the proper signal through the analogue board connector, pin 20 cannot be grounded but must rather be connected to pin 3 somehow.

I'd be willing to bet that on the boards without J78/79, making sure pin 20 is disconnected from ground and tying it to pin 3 with a short wire will do the trick. If anyone can report success on this, please let me know as I don't have the right analogue board to try it myself.

cl

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